1. Related Invention
This application is related to the invention disclosed in an application entitled "Self-contained Bore Hole Flow Measurement System and Method Therefor", Ser. No. 686,513 by the present inventor and filed concurrently on the same date as this application.
2. Technical Field
This invention relates to baskets for determining flow rates in oil wells and, more particularly, to an improved flow basket having formed petals that move only in one direction.
3. Background Art
As set forth in the above identified co-pending application, one important parameter of oil well production is the determination and measurement of the flow in the well at various production levels in the bore hole. Therefore, this invention relates to a type of flow basket adapted for use in the measurement of fluid velocities in wells.
Prior to the present application, the inventor effectuated a patentability search on flow baskets which uncovered the following patents:
______________________________________ Inventor Reg. No. Issue Date ______________________________________ M. M. Kinley 1,979,802 Nov. 6, 1934 C. R. Dale 2,649,710 Aug. 25, 1953 C. R. Dale 2,649,711 Aug. 25, 1953 R. P. Vincent 2,706,406 Apr. 19, 1955 J. A. Hall 3,119,451 Jan. 28, 1965 H. L. Bryant 3,163,038 Dec. 29, 1964 J. J. Glenn, Jr. 3,195,042 July 13, 1965 R. H. Widmyer 2,932,740 Apr. 12, 1960 J. R. Solum 3,385,368 May 28, 1968 Hughes et al. 3,955,625 May 11, 1976 ______________________________________
The patent issued to Hall discloses a cement basket having a plurality of petals which are allowed to move freely within outward metal bow strings around the basket. The bow strings are attached to collars which slide along the shaft and engage fixed stops. The metal basket selectively opens and closes and is able to rotate about the shaft. In one embodiment, one of the bow string collars is affixed to the shaft. The patents to Solum et al. and Hughes et al. also disclose other types of cementing baskets.
The patents to Dale, Vincent and Bryant relate to flowmeters. The two Dale patents show a trap composed of opening and closing extended metallic fingers attached to circularly overlapping metallic vanes. The Vincent patent directs the flow by means of a packer into an impeller sensor. The packer Vincent, which is made of flexible material, is disposed under a plurality of bow strings and moves from a collapsed state to an open state. The Bryant fluid diverter also utilizes a basket under the bow strings. Both ends of the Bryant basket are affixed to the bow strings. In Bryant, the ends of the bow string attached to the end of the basket are also affixed to the shaft whereas the opposite ends of the bow strings are attached to a ring that travels along the shaft with the opening and closing of the basket. The remaining patents uncovered in the search are not close to the present invention as those discussed above.
Another prior art reference is the commercially available powered flow diverter, Model 5500, manufactured by OI Corporation, Graham Road at Welborn Road, P.O. Box 2980, College Station, Tex. In this approach, one end of the basket is allowed to slide along the shafts whereas the bow strings are affixed the entire longitudinal length of each petal to a fixed connection at the bottom end of the petal.
The OI Corporation product and the Bryant patent are believed to be pertinent to the teachings of the present invention. However, in both devices, movement of the petal in two or more directions can occur thereby causing buckling or distortion of the petal under normal operating conditions. Such buckling is undesirable as it may cause leaks or breakdown of the basket. In other words, in these two approaches, not only does outward radial movement of the basket occur but also circular or other movement which thereupon causes the buckling of the metal vanes. The present invention has for its goal the elimination of this problem as set forth next.